Move assertion to after context is printed

When hitting the assertion it's highly useful to see the WARNING
printed by the elog() as context for debugging. Move the assertion
to after the elog() call to ensure it's visible before erroring out.

src/backend/tcop/utility.c

@@ -2819,9 +2819,9 @@ CreateCommandTag(Node *parsetree)
 			break;
 
 		default:
-			Assert(false);
 			elog(WARNING, "unrecognized node type: %d",
 				 (int) nodeTag(parsetree));
+			Assert(false);
 			tag = "???";
 			break;
 	}